The above-mentioned operating method and the associated devices are used inter alia to capture angiographic photographs (=two-dimensional images) of coronary vessels in a human heart and to then determine the number, length, diameter, etc. of the coronary vessels. Evaluation of the images for measuring the blood flow rate is also known.
A further application of the above-mentioned operating method and the associated devices consists in capturing a sequence of images of the beating heart (or, more generally, an iteratively moving object being examined) over a relatively long time. The sequence of images is captured in this case in response to a user's corresponding start input. Capturing instants of the images and a phase signal (in the case of a beating heart an ECG signal for example) are captured at the same time as the images. The sequence of images, capturing instants and the phase signal are then archived for subsequent evaluations.
With the aid of such sequences what is referred to as the myocardial blush may for example be captured, on the basis of which statements about the blood supply to the heart may be made.
Assessing the blood circulation of the myocardium is associated with difficulties however as it is ultimately a matter of the blood circulation in the tiny capillary vessels which have diameters of only a few micrometers and in which the exchange of oxygen takes place. The angiographically observable cardiac vessels have a diameter of scarcely one millimeter or more, however. A conclusion about the blood circulation of the capillary vessels from the blood circulation of the angiographically observable cardiac vessels is not automatically correct or admissible, however.
The dynamics of the blood flow in the capillary vessels can in principle be detected in the angiographic images by the general (i.e. not localized to individual vessels) contrast enhancement. Owing to problems in application and interpretation this enhancement in the contrast is not generally used, however. In the prior art one therefore often still manages by making conclusions about the blood circulation of the capillary vessels from the blood circulation of the larger coronary vessels.
In order to render the blood flow dynamics in large vessels and the capillary vessels measurable and therefore comparable, various gradation systems are used which divide the continuum of the relationships into discrete classes. Various classifications of this type describe the macroscopic blood circulation and others the capillary blood circulation. The most used classifications have been developed by the scientific organization “Thrombolysis in Myocardial Infarction (TIMI)”. These classifications are considered the standard but are complex and merely time-consuming to use. The TIMI classifications are frequently used in multi-centric studies in which the particular focus is on reproducible and comparable results. However, these classifications are not generally applied in routine clinical work. In addition, owing to the individual blush evaluations very different results are produced (in particular with different users).